1. Field of the Invention
This invention relates to the delivery of vaccines and more particularly it concerns novel methods and apparatus for packaging and dispensing vaccines of the type which are administered by injection through a needle.
2. Description of the Prior Art
In general, vaccines, after being harvested from a culture tank, are clarified, diluted, subdivided into vials or ampules and then lyophilized. When lyophilized the vaccine may be kept for extended periods of time at a temperature not above about 8.degree. C., typically from about -20.degree. C. to about 8.degree. C., with losses substantially below those encountered in aqueous vaccines. A long unmet need has been the providing of a low cost single dose delivery system for a lyophilized vaccine.